Keir Starmer may be on a collision course with Donald Trump after the US president said he was not going to offer many security guarantees to Europe.
While on the plane to Washington DC to meet with Trump, the prime minister told reporters that Vladimir Putin will “come again” unless the US protects Ukraine as part of any peace deal.
And a senior No.10 source told HuffPost UK: “Stopping the fighting in Ukraine is not enough. It has to be a lasting peace - which needs US backup.”
But before Starmer had even touched down in the States, the US president told his cabinet: “I’m not going to make security guarantees beyond very much. We’re going to have Europe do that.”
Trump’s comments throw a spanner in the works for Starmer, who wants to be seen as a “bridge” between the US and Europe amid concerns about Vladimir Putin’s long-term ambitions.
The PM even promised to take defence spending from 2.3% of gross domestic product (GDP) to 2.5% by 2027 shortly after Trump made it clear the US is no longer willing to offer military support to Europe.
Starmer has suggested deploying a UK peacekeeping force – if a peace agreement is reached – to Ukraine as well, as long as it was accompanied by a “US backstop”.
The president is pushing to end Ukraine war sooner rather than later but appears to be giving in to all of Putin’s demands for peace in the process – including potentially forcing Ukraine to cede occupied territory to Russia.
This has sparked fears the Russian leader will return to grab more of Europe in the future.
Starmer told journalists travelling on his plane: “The reason I say the backstop is so important is that the security guarantee has to be sufficient to deter Putin from coming again.
“Because my concern is if there is a ceasefire without a backstop, it will simply give him the opportunity to wait and to come again because his ambition in relation to Ukraine is pretty obvious, I think, for all to see.”
But officials have not explained just what security guarantees will be asked of Trump.
The PM said: “It’s got to be a lasting peace, and that requires us to put in place an effective security guarantee.
“Exactly what the configuration of that is, exactly what the backstop is, is obviously the subject of intense discussion.”
Starmer also told reporters Trump is “clearly committed to Nato,” despite his past threats to pull out of the defence alliance.
He added that “of course” Trump knows Putin is the aggressor in Ukraine and said, “there’s no issue between us on this”.
The US president did refuse to call the Russian leader a dictator earlier this week though, despite falsely using the label for Ukrainian president Volodymyr Zelenskyy.
Although Starmer has criticised Trump in the past, the US president has praised him repeatedly since he was elected, saying: “I think he’s a very good person and I think he’s done a very good job thus far.”
Starmer’s visit comes after his ally French president Emmanuel Macron made a similar journey to the White House earlier this week.
Zelenskyy is set for his own face-to-face with Trump this Friday, where the US president has suggested they will be signing a “very big agreement” about sharing Ukraine’s mineral deposits.
The Ukrainian president will then come to the UK to meet Starmer and Neto secretary-general Mark Rutte on Sunday to discuss any progress on security guarantees.